1. Technical Field
The present invention relates to a concentricity-detecting apparatus and method for precisely detecting a level/degree of concentricity of a lens module.
2. Description of Related Art
Nowadays, with the development of the optical imaging technology, camera modules are now in widespread use. Camera modules are being combined with various portable electronic devices such as mobile phones, PDAs (personal digital assistants) and portable computers, to make such devices increasingly multi-functional.
A typical camera module generally has a lens module mounted therein. The lens module is coupled with an image sensor such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) so as to capture images. Generally, the lens module includes a holder and a barrel pivotably received in the holder. A plurality of lenses and spacers is alternately received in the barrel. Preferably, an infrared-cut filter that blocks light in the infrared spectrum is also fitted in the lens module to prevent interference. Before the qualified lens module is entered in a market, the imaging quality of the lens module after assembly must be ensured. Accordingly, the degree/level of the concentricity of the holder and the barrel therein the hold must be detected, in order to ensure that the camera qualifies to be sold on the market.
Conventionally, manual detection for concentricity of the lens module has low efficiency and speed, to a certain degree. Further, the concentricity of the lens module may not be precisely measured, due to operators error and/or skill limitations. Therefore, it is nearly impossible to ensure that every detected lens module is qualified when relying on manual inspection.
An improved apparatus and method for precisely detecting concentricity of the lens module is thus desired to thereby overcome the above-mentioned disadvantages. What is needed, therefore, is a detecting apparatus and method for precisely detecting/measuring the level/degree of concentricity of a lens module.